Do Safety Warnings Change Prescribing among the U.S. Dialysis Population? Objectives on March 9, 2007, FDA issued a public health advisory and Black Box warning outlining new safety information, including revised product labeling about erythropoiesis- stimulating agents (ESAs), widely-used drugs for the treatment of anemia associated with renal disease. The goal of this proposal is to determine if these new recommendations resulted in a change in physician prescribing among all US dialysis patients covered by the Medicare End-Stage Disease (ESRD) program. Methods Computerized United States Renal Disease System (USRDS) data from March 2006 through March 2009 are proposed to evaluate prescribing patterns in the year before and two years after the FDA Public Health Advisory. An interrupted time series model, based on all outpatient dialysis encounters indicating use of ESAs will be used to assess the impact of the FDA Black Box Warnings in influencing physician prescribing. Results - We will show trends in prescribing of ESAs for anemia associated with renal failure (commonly found among nearly all dialysis patients) before and after the FDA warnings. We will assess whether changes in prescribing can be attributed to the FDA Public Health Advisory. Results will be stratified by patient demographics (age, race, gender), responsiveness to therapy (achieved hemoglobin >10 g/dL), cause of ESRD (diabetes, hypertension, etc.), vintage (length of time on dialysis), and facility characteristics (chain status, size of facility and profit status). Conclusions/Implications We will show whether two years after a highly publicized FDS Public Health Advisory (a Black Box Warning that went out to all practicing nephrologists) indicating the safety risks associated with ESA therapy and recommendations to use 'the lowest dose possible to avoid blood transfusions'resulted in a decline in the previously high ESA doses observed among dialysis patients. Using 'real world'prescription data among a census of Medicare ESRD patients on dialysis, we will investigate whether the FDA recommendations from the March 2007 advisory meeting were coincident with a change in physician prescribing patterns. We will show whether - without accompanying changes in the reimbursement structure, i.e., higher ESA doses continued to be profitable during our study period - physicians changed their ESA prescribing habits as a result of the FDA warnings. This study presents a unique opportunity to examine the dissemination of grave Black Box warnings and the willingness of physicians to modify prescribing habits in treating a vulnerable population of dialysis patients. PUBLIC HEALTH RELEVANCE: Do Safety Warnings Change Prescribing among the U.S. Dialysis Population? Our proposed study provides critical information to physicians, decision-makers, policymakers, and society overall regarding the role of 'predisposing factors'such as an expert advisory recommendation in changing physician prescribing behavior. Given AHRQ's strong and demonstrated commitment to the improvement of society through the exchange of information and ideas that should lead to greater access and usage of ethical medical treatments, this study will lead to a better understanding of the health and economic outcomes from use of an expensive and somewhat controversial therapy. Our study specifically provides important information regarding factors that influence use of drugs, particularly those with safety issues such as ESAs. How best to prescribe certain drugs to both enhance their effectiveness as well as to diminish their risks is challenging. Advice from government entities such as FDA and other clinical experts is thought to play an important role in this arena. Our study tests this hypothesis by examining whether there has been a decline in drug doses within a two year period following an expert panel recommendations and Black Box warnings that went out to all practicing nephrologists recommending "the lowest dose of ESA therapy possible....". This study presents a unique opportunity to examine the dissemination of grave Black Box warnings and the willingness of physicians to modify prescribing habits in treating a vulnerable population of dialysis patients.